Many applications exist for enzymes that have higher activities at temperatures lower than the currently available enzymes used in cleaning. For example, enzymes that remain active in cool and warm water would be useful for removing stains from clothes during lower temperature laundry conditions. This would decrease the energy consumption normally used to heat laundry water and would reduce the negative energy impact on the environment. Enzymes effective at lower temperatures would permit washing delicate or brightly colored fabrics in conditions that cause less shrinkage and dye bleeding. Under these low temperature conditions, stain removing enzymes which maintain high activity at low temperatures will remove more stain material from clothing than currently used higher water temperature active enzymes.
Most currently available enzymes, including Savinase, have a higher temperature optima (45.degree. C.-55.degree. C.) and must be used at high water temperatures to be effective. The advantage of a low water temperature stain removing enzyme, if found, would be its ability to achieve the desired stain removal at lower temperatures, requiring less time and energy and offering less risk of substrate damage.
Enzymes effective at low temperatures could have additional utilities and applications not possible with currently available enzymes. For example, such enzymes could be used for other consumer applications such as household cleaners, with or without added surfactants. They could have utility in the baking and food processing industries where enzyme activity at lower temperatures allows faster processing or cleaning treatments at reduced temperatures which in turn lower the risk of growth of spoilage organisms. Other advantages of enzymes with higher activities at low temperatures include, but are not limited to, bioremediation in cool climates, industrial chemical conversions, scientific research, etc.
Hydrolase enzymes are standard additions to both liquid and solid cleaning, treating or laundering compositions. One of the concerns in adding hydrolases to such formulations has been stability (i.e., retaining hydrolytic activity) because of close association in the formulation with materials which may be inimical to stability, such as, without limitation, oxidants, water (moisture), heavy metals, or other materials which may decompose, denature or deactivate hydrolases.
One method of protecting enzymes is to encapsulate them. This is demonstrated in Coyne, et al., U.S. Pat. Nos. 4,863,626, 5,093,621, and 5,225,102, and DeLeeuw, et al., U.S. Pat. No. 5,254,287 and 5,167,854. Another method is to isolate, by means of a protective reticulum, or by preventing the premature solubilization of oxidants in a liquid matrix in which the enzymes are suspended, for example, in, respectively, Sells, et al., U.S. Pat. No. 5,789,364 and Koerner, et al., U.S. Pat. No. 5,589,448, and Peterson, et al., U.S. Pat. No. 5,464,552. All of the foregoing patents are incorporated herein by reference.
Hydrolase activity can subside in the course of storage of the hydrolase within a cleaning or laundering or treatment product, so executing such products to enhance the enzymes' activity is important for good stain removal performance. Examples of this can be seen in Stanislowski, et al., U.S. Pat. No. 4,511,490 (synergistic combinations of alkaline proteases), and Stanislowski, et al., U.S. Pat. No. 5,364,554 (enzyme-mediated perhydrolysis).
Of course, recently much work has been conducted to locate new enzymes which present new and different advantages over commercially available enzymes. For example, Leigh, U.S. Pat. No. 5,646,028 demonstrates that a protease enzyme isolated from Streptomonas griseus sp. will have greater activity and stain removal performance than a wild strain of S. griseus. Further, an engineered protease has been found to have greater activity than commercially available enzymes. See, Poulose, et al., U.S. Pat. No. 5,108,457.
Recently, researchers have been screening certain bacteria for hydrocarbon-degrading properties. See, for example, WO 98/27015 and WO 98/20836.
However, there has heretofore been nothing in the literature which teaches, discloses or suggests that hydrolase enzymes derived from a novel bacterial isolate which has been designated as Strain 177 by researchers from Pennsylvania State University, combined with at least one cleaning, laundering or treating additive, will have surprisingly effective low temperature stain removal performance.
From the above description it can be seen that it would be desirable, or there is a need to develop low temperature activated proteolytic enzymes useful for a wide variety of effective stain removing compositions, with or without surfactants. Versatile proteolytic enzymes having low temperature effectiveness for stain removal could be used in liquid or granular detergents, liquid or granular stain removers, prewashes, household cleaners, and in food and industrial cleansing applications. This invention has as its primary objective the fulfillment of these needs.